Divided Representation of Concurrent Goals in the Human Frontal Lobes

Abstract

Simultaneously Serving Two Goals What are the neuronal mechanisms underlying dual-task performance? Charron and Koechlin (p. 360 ) used functional magnetic resonance imaging to study this question under conditions of varying incentive for two tasks. Subjects performed letter-matching tasks either sequentially or concurrently. Reward value for performance of each of the two tasks was manipulated orthogonally. Under conditions of single-task (sequential) performance, they observed bilateral brain activity in the dorsal anterior cingulate and the premotor cortex that correlated with the reward value of the current task. However, under dual-task conditions, activity in these regions on the left corresponded to primary-task reward performance, while on the right, activity corresponded to secondary-task performance. Under dual-task conditions, both reward and stimulus-response representations are thus segregated according to hemisphere.